CNN is holding its first televised debate among Republican presidential candidates tonight, but while the cable news network has issued invitations to several non- or yet-to-announce candidates, it is excluding one announced candidate who meets the criteria for inclusion. Former New Mexico Gov. Gary Johnson, an avowed and articulate opponent of drug prohibition, was not invited to participate, and his campaign and supporters are crying foul.

CNN, along with WMUR-TV and the Manchester Union-Leader, the debate cosponsors, set the bar for an invitation at the candidate having received an average of at least 2% in at least three national polls during the month of May. According to the Johnson campaign, Johnson has met that hurdle, polling an average of precisely 2% in three national polls last month.

“It is our hope that CNN will review the criteria that has excluded two-term Governor Gary Johnson from the New Hampshire debate,” said senior Johnson campaign advisor Ron Nielson on Saturday. “Now that this information has come to light, we look forward to receiving an invitation for Governor Johnson to participate.”

Most of the invitations are well-justified. According to Real Clear Politics’ aggregate poll data (which also does not include Johnson) all of the invitees are above 2%, although Santorum, at 3.2% overall, only averaged 2.67% in three May polls. Non-announced candidate Bachmann is averaging 5.1%, although that’s a decline from her May poll average of 7%.

Still, why Johnson was excluded even though he has officially announced and meets the debate criteria remains a mystery. CNN said it only wanted “serious” candidates with at least 2% of the vote, but also admitted it failed to include Johnson in its own polls.

Well, Republican-leaning drug reformers will at least have Ron Paul to listen to tonight.